That other person has already punched. Iran punched the US first with embassy attack. The US counter punched back very hard between the eyes. Now both sides got their punch in. They don’t want to fight and die. Now they use verbal threats to deter the other from further attack.
Iran won’t do foolish things to push the US into a corner. Survival is the number one priority of human beings.
With all due respect you hardly have anything to back your assertions up with other than saying that they both got their respective punches in ad hominem. No, they most definitely did not. One punched the other way harder, and Iran will respond, they've already made up their mind.
The killing of Soleimani was way out of proportion due to who he was, he wasn't just some field general, the man was a diplomat and go-between for Iran and other regional leaders as well as being the No.2 in all of Iran directly behind Ali Khamenie himself. Countries just don't go around murdering high level officials willy nilly, and this action
did not whatsoever make the situation better.
This sort of death will warrant (and Iranian retribution is coming no matter what you say to the contrary) an equal or possibly more deadly revenge attack back.
The red flag over the Jamkaran Mosque in Qom city as well as every Iranian offical both policy makers and military saying there will be a military response is already telling enough as to what will happen. Iran has said it time and time again, they might not want a conflict but they aren't afraid to get into one.
Trump's latest tweet almost certainly painted the U.S. and Iran into a corner that will only lead to war, possibly a High intensity limited confrontation but one that will cause insane amounts of physical damage to key oil installations the region over.
Again, the decision haS already been made to draw blood for this killing, not some useless American grunts mind you, whoever Iran is planning to kill will be important to critical functions for the U.S. in the middle east, just as Soleimani was critical to Iranian operations in the Middle East.
I'll be fair and give your pragmatic stance a point though, Iran could and most likely will leave the JCPOA and NPT in the future, there is also the Iraqi parliamentary vote to kick out the U.S. troops from Iraqi soil which can also help abate Iranian emotions. This could be enough retribution in of itself as it would pave the way for Iran to build a nuke and establish long lasting deterrence but everything Iran has said and the militias in Iraq have said is to the contrary of your pragmatic take on this.
To put it bluntly, just because nations have a lot to lose doesn't mean they won't risk losing it. It is not outside the realm of possibility that we see a large scale limited high-intensitiy confrontation between Iranian and American forces. In fact, it has quite a good chance of going down.